Genus 20. 



CROWFOOT FAMILY. 



115 



31. Ranunculus muricatus L. Spiny- 

 fruited Crowfoot. Fig. 1925. 



Ranunculus muricatus L. Sp. PI. 555. 1753. 



Annual, glabrous or sparingly pubescent, 

 branched from the base, i°-2° high. Lower 

 and basal leaves on long broad petioles, the 

 blade reniform or cordate-orbicular, i'-2' 

 wide, 3-lobed, cleft, or crenate ; the upper 

 3-divided, cuneate, short-petioled or sessile ; 

 flowers light yellow, 3"-s" wide, the petals 

 exceeding the calyx; head of fruit globular, 

 5"-6" wide ; achenes flat, with a broad smooth 

 margin, densely muricate and spiny on the 

 sides, 2" long, tipped with a stout slightly 

 curved beak of one-half their length, the stout 

 margin unarmed. 



Waste places and fields, eastern Virginia to 

 Arkansas, Florida and Texas. Bermuda. Natu- 

 ralized or adventive from Europe. Also on the 

 Pacific Coast. Native also in Asia. Summer. 



32. Ranunculus arvensis L. Corn Crow- 

 foot. Hunger-weed. Fig. 1926. 



Ranunculus arvensis L. Sp. PI. 555. 1753. 



Erect, glabrous or sparingly pubescent, 

 branched above, 1° or more high. Lower 

 leaves petioled, the upper sessile, all deeply 

 cleft or divided into linear-oblong, obtuse 

 cuneate, lobed or toothed segments or the low- 

 est entire; flowers 6"-8" broad, pale yellow, 

 the petals exceeding the sepals; achenes 4-8, 

 flattened, margined, spiny-tuberculate on the 

 sides and margin, 2" long, tipped with a sub- 

 ulate beak more than one-half their length. 



In waste grounds, southern New York and New 

 Jersey to Ohio, and in ballast. Fugitive from 

 Europe, where it is abundant in grain-fields. 

 Called Hunger-weed because supposed to indicate, 

 when prevalent, a poor crop and consequent want. 

 Starve-acre. Devil's-claws. Hell-weed. Horse- 

 gold. Gold-weed. Summer. 



21. BATRACHIUM S. F. Gray, Nat. Arr. Brit. PI. 2: 720. 1821. 



Perennial aquatic or ditch herbs, with alternate dissected or palmately lobed leaves, the 

 segments of the submerged ones often filiform, and solitary rather small white flowers, 

 borne on peduncles opposite the leaves. Sepals and petals usually 5. Petals oblong or 

 oval, the base sometimes yellowish, the claw bearing a small pit. Stamens several or nu- 

 merous. Achenes oblique, compressed, not margined, beakless or short-beaked, transversely 

 wrinkled. [Greek, referring to the aquatic habitat.] 



About 20 species of very wide geographic distribution. Besides the following, several others 

 occur in western North America. Type species: Batrachium hederaceum (L.) S. F. Gray. 



Leaves all dissected into filiform segments and lobes. 



Leaves i'-2' long, flaccid, collapsing when taken from the water. i. B. trichophyllnm. 



Leaves i' long or less, rigid when taken from the water. 2. B. circinatuni. 



Leaves all reniform or broadly ovate, 3-5-lobed, 5"-io" wide. 3. B. hederaceum. 



